Frame structure aware compression for multi-input multi-output (MIMO) systems

Abstract

A multi-antenna apparatus of a multi-input multi-output (MIMO) communication system for compressing and decompressing a frequency domain digital signal are provided, wherein a data channel type of each frequency-domain digital sub-signal of the frequency-domain digital signal is determined by a radio frame structure map (π). The multi-antenna apparatus includes a respective compressor and a respective decompressor associated to each data channel type, and is configured, for each frequency-domain digital sub-signal of the frequency-domain digital signal, to compress, at a first module, the frequency-domain digital sub-signal using the compressor associated to the data channel type of the frequency-domain digital sub-signal, and, for each compressed frequency-domain digital sub-signal, to decompress, at a second module communicating with the first module via an FH link, the compressed frequency-domain digital sub-signal using the decompressor associated to the data channel type of compressed frequency-domain digital sub-signal.

What is claimed is: 
     
       1. A multi-antenna apparatus of a multi-input multi-output (MIMO) communication system for compressing and decompressing a frequency-domain digital signal, wherein:
 the frequency-domain digital signal (X) is composed of frequency-domain digital sub-signals (X(i, j, k)) and is allocated to a respective resource block (RB), each RB comprising multiple resource elements (REs) according to a frequency-time grid; 
 each frequency-domain digital sub-signal is allocated to a respective RE of the RB; and 
 each frequency-domain digital sub-signal has a data channel type amongst at least one data channel type, the data channel type of each frequency-domain digital sub-signal being determined by a radio frame structure map, 
 the multi-antenna apparatus comprising a respective compressor and a respective decompressor associated with each data channel type, 
 the multi-antenna apparatus being configured to:
 for each frequency-domain digital sub-signal of the frequency-domain digital signal, select, at a first module, the respective compressor associated with each data channel type based on each frequency-domain digital sub-signal and the radio frame structure map; compress, at the first module, the frequency-domain digital sub-signal using the selected compressor associated with the data channel type of the frequency-domain digital sub-signal; and 
 for each compressed frequency-domain digital sub-signal, decompress, at a second module communicating with the first module via a fronthaul (FH) communication link, the compressed frequency-domain digital sub-signal using the decompressor associated to the data channel type of compressed frequency-domain digital sub-signal. 
 
 
     
     
       2. The multi-antenna apparatus of  claim 1 , wherein before selecting the respective compressor, the apparatus is further configured to:
 receive, from a signal generator at the first module, the frequency-domain digital signal and the radio frame structure map; 
 detect, at the first module, the frequency-domain digital sub-signals of the frequency-domain digital signal according to the data channel type determined by the radio frame structure map. 
 
     
     
       3. The multi-antenna apparatus of  claim 2 , further configured to:
 compress, at the first module, the radio frame structure map using a lossless compressor. 
 
     
     
       4. The multi-antenna apparatus of  claim 3 , further configured to:
 determine, at the first module, a set of compression parameters, which are used for the compression of the detected frequency-domain digital sub-signals per data channel type. 
 
     
     
       5. The multi-antenna apparatus of  claim 4 , further configured to:
 transmit, the set of compression parameters, the compressed radio frame structure map and the compressed frequency-domain digital sub-signals per data channel type, from the first module towards the second module via the FH link. 
 
     
     
       6. The multi-antenna apparatus of  claim 5 , further configured to:
 receive, at the second module, the set of compression parameters, the compressed radio frame structure map and the compressed frequency-domain digital sub-signals per data channel type; 
 decompress, at the second module, the compressed radio frame structure map using the lossless decompressor, as to obtain the radio frame structure map; 
 detect, at the second module, the compressed frequency-domain digital sub-signals of the compressed frequency-domain digital signal according to the data channel type determined by the radio frame structure map; and 
 select, at the second module, the respective decompressor per data channel type in order to decompress the compressed frequency-domain digital sub-signals per data channel type. 
 
     
     
       7. The multi-antenna apparatus of  claim 6 , further configured to:
 provide, at the second module, the set of compression parameters to each decompressor per data channel type, the set of compression parameters being used for the decompression of the detected compressed frequency-domain digital sub-signals per data channel type. 
 
     
     
       8. The multi-antenna apparatus of  claim 7 , further configured to:
 reconstruct, at the second module, the frequency-domain digital signal using the decompressed compressed frequency-domain digital sub-signals and the radio frame structure map, 
 wherein the reconstructed frequency-domain digital signal is composed of all the decompressed compressed frequency-domain digital sub-signals allocated to all the REs of the respective RB. 
 
     
     
       9. The multi-antenna apparatus of  claim 8 , further configured to:
 convert, at the second module, the reconstructed frequency-domain digital signal to a time-domain digital signal. 
 
     
     
       10. The multi-antenna apparatus of  claim 1 , wherein the first module is a base band unit (BBU) and the second module is a radio resource unit (RRU). 
     
     
       11. The multi-antenna apparatus of  claim 1 , wherein the first module is an RRU and the second module is a BBU. 
     
     
       12. A method for compressing and decompressing a frequency-domain digital signal within a multi-input multi-output (MIMO) communication system, wherein:
 the frequency-domain digital signal (X) is composed of frequency-domain digital sub-signals (X(i, j, k)) and is allocated to a respective resource block (RB), each RB comprising multiple resource elements (REs) according to a frequency-time grid; 
 each frequency-domain digital sub-signal is allocated to a respective RE of the RB; and 
 each frequency-domain digital sub-signal has a data channel type amongst at least one data channel type, the data channel type of each frequency-domain digital sub-signal being determined by a radio frame structure map, 
 the method comprising:
 for each frequency-domain digital sub-signal of the frequency-domain digital signal, selecting, at a first module, a respective compressor associated with each data channel type based on each frequency-domain digital sub-signal and the radio frame structure map; compressing, at the first module, the frequency-domain digital sub-signal using the selected compressor associated with the data channel type of the frequency-domain digital sub-signal; and 
 for each compressed frequency-domain digital sub-signal, decompressing, at a second module communicating with the first module via a fronthaul (FH) communication link, the compressed frequency-domain digital sub-signal using a decompressor associated to the data channel type of compressed frequency-domain digital sub-signal. 
 
 
     
     
       13. The method of  claim 12 , further comprising:
 receiving, from a signal generator at the first module, the frequency-domain digital signal and the radio frame structure map; 
 detecting, at the first module, the frequency-domain digital sub-signals of the frequency-domain digital signal according to the data channel type determined by the radio frame structure map; 
 and 
 compressing, at the first module, the radio frame structure map using a lossless compressor. 
 
     
     
       14. The method of  claim 13 , further comprising:
 receiving, at the second module, a set of compression parameters from the first module, the compressed radio frame structure map and the compressed frequency-domain digital sub-signals per data channel type; 
 decompressing, at the second module, the compressed radio frame structure map using the lossless decompressor, as to obtain the radio frame structure map; 
 detecting, at the second module, the compressed frequency-domain digital sub-signals of the compressed frequency-domain digital signal according to the data channel type determined by the radio frame structure map; and 
 selecting, at the second module, the respective decompressor per data channel type in order to decompress the compressed frequency-domain digital sub-signals per data channel type. 
 
     
     
       15. The method of  claim 14 , further comprising:
 reconstructing, at the second module, the frequency-domain digital signal using the decompressed compressed frequency-domain digital sub-signals and the radio frame structure map, 
 wherein the reconstructed frequency-domain digital signal is composed of all the decompressed compressed frequency-domain digital sub-signals allocated to all the REs of the respective RB. 
 
     
     
       16. A non-transitory computer readable medium comprising program codes which, when executed by a computer, cause the computer to perform a method for compressing and decompressing a frequency-domain digital signal within a multi-input multi-output (MIMO) communication system, wherein:
 the frequency-domain digital signal (X) is composed of frequency-domain digital sub-signals (X(i, j, k)) and is allocated to a respective resource block (RB), each RB comprising multiple resource elements (REs) according to a frequency-time grid; 
 each frequency-domain digital sub-signal is allocated to a respective RE of the RB; and 
 each frequency-domain digital sub-signal has a data channel type amongst at least one data channel type, the data channel type of each frequency-domain digital sub-signal being determined by a radio frame structure map, 
 the method comprising:
 for each frequency-domain digital sub-signal of the frequency-domain digital signal, selecting, at a first module, a respective compressor associated with each data channel type based on each frequency-domain digital sub-signal and the radio frame structure map; compressing, at the first module, the frequency-domain digital sub-signal using the selected compressor associated with the data channel type of the frequency-domain digital sub-signal; and 
 
 for each compressed frequency-domain digital sub-signal, decompressing, at a second module communicating with the first module via a fronthaul (FH) communication link, the compressed frequency-domain digital sub-signal using a decompressor associated to the data channel type of compressed frequency-domain digital sub-signal. 
 
     
     
       17. The non-transitory computer readable medium of  claim 16 , wherein before selecting the respective compressor, the method is further configured to:
 receive, from a signal generator at the first module, the frequency-domain digital signal and the radio frame structure map; 
 detect, at the first module, the frequency-domain digital sub-signals of the frequency-domain digital signal according to the data channel type determined by the radio frame structure map. 
 
     
     
       18. The non-transitory computer readable medium of  claim 17 , further configured to:
 compress, at the first module, the radio frame structure map using a lossless compressor. 
 
     
     
       19. The non-transitory computer readable medium of  claim 18 , further configured to:
 determine, at the first module, a set of compression parameters, which are used for the compression of the detected frequency-domain digital sub-signals per data channel type. 
 
     
     
       20. The non-transitory computer readable medium of  claim 19 , further configured to:
 transmit, the set of compression parameters, the compressed radio frame structure map and the compressed frequency-domain digital sub-signals per data channel type, from the first module towards the second module via the FH link.